Neil Smith just published a short book on Jason and the Argonauts in ebook format. It's interesting in that it has lots of pictures and maps, plus it goes into some of the variations of the different versions of the myth.

(Note that these are only the Greek and Roman myths.) I had read this in High School, then recently got a hankering to read it again. It's long out of print, but used copies are cheap on Amazon. A wonderful explanation of the origins of many English words and figures of speech .

For Mayan (Central America) mythology check out the Popol Vuh. The Tedlock version is what I was told to read by the experts in the field back in the mid-90s. There is also an animated film using pre-Columbian Mayan artwork if you would like to watch mythology in action.